With respect to pipe sleeves secured about portions of a pipeline, when the pipeline is made of plastic pipe, any distortion of the cross-sectional area portions of the plastic pipe should preferably be avoided or held to a minimum allowable distortion. Most pipe sleeve assemblies when made of cast components in a way to avoid or to limit plastic pipe distortion, become quite expensive. Also some fabricated pipe sleeve assemblies, not having transversely extending lug portions, when tightened, cause unwanted distortion of plastic pipes. Such sleeves which are effective with respect to sealing about metal pipe, but are less effective with respect to sealing about a larger plastic pipe, are illustrated, for example, in U.S. Pat. Nos. 4,708,373, and 5,040,828.
Transversely extending lug portions are illustrated in U.S. Pat. No. 3,189,970. They are shown in respect to an all stainless steel repair clamp.
There continues to be a need to have lower cost pipe sleeves, which upon tightening keep the overall shell gasket in an excellent sealing position, while either not distorting a plastic pipe or only creating a limited distortion of a plastic pipe, thereby either not stressing nor overstressing a plastic pipe.